JP5519443B2 - Seal front end protection structure - Google Patents

Description

  The present invention relates to the direction of propulsion between the adjacent preceding tunnel and the succeeding tunnel in order to stop water between the inside and outside of the large section tunnel constructed by using a plurality of tunnels arranged in parallel by the propulsion method. It is related with the seal front-end part protection structure which protects the front-end part of the elastic seal member provided along.

  In recent years, after constructing multiple small cross-section tunnels, unnecessary lining of each tunnel is removed to form a large space, while the remaining lining of each tunnel is used to construct the top plate and sidewall A technique for constructing a large-section tunnel is known by forming, for example. Note that the plurality of small-section tunnels are sequentially constructed with a time difference, and the succeeding tunnel is constructed next to the preceding tunnel. Each tunnel is constructed by, for example, a propulsion method.

  Here, the propulsion method is a method of constructing a tunnel by sequentially press-fitting a cylindrical propulsion box (tunnel box), which becomes a tunnel lining, into the ground from a wellhead. In addition, a blade edge, an excavation machine, etc. are attached to the front-end | tip of a propulsion box. The propulsion method excavator may be one that digs itself by taking a reaction force to the propulsion box (that is, one that is equipped with a propulsion jack), or the thrust of the main jack transmitted through the propulsion box You may dig by.

  By the way, when constructing a small-section tunnel by the propulsion method, especially when the propelling box is pushed out from the rear of the tunnel with a main jack, the trailing tunnel may not be propelled in parallel to the preceding tunnel. Therefore, in order to drive the preceding tunnel in parallel along the succeeding tunnel, one of the two adjacent tunnels is formed with a guide groove opened along the tunnel axis in the other tunnel side. For the other tunnel, a large-section tunnel is proposed in which a ridge that is loosely fitted in the guide groove of one tunnel is formed (see, for example, Patent Document 1).

  In the large-section tunnel having such a configuration, a gap between adjacent tunnels is sealed by filling a water stop material between the ridge and the guide groove. However, the large-section tunnel described above has a problem that construction requires a lot of labor and time because the guide groove is cleaned to fill the water stop material after the clogged back material is removed. It was.

  Therefore, the present inventors have developed a water stop structure that can be easily constructed to solve the above problems (see Patent Document 2). This water stop structure includes a linear elastic seal member provided along the propulsion direction on the outer surface of one of adjacent tunnels facing the other tunnel, and the elastic seal member A base portion fixed to the outer surface of the tunnel, and a lip portion integrally formed with the base portion and having a tip facing the outside of the large-section tunnel, the lip portion is a pressure outside the large-section tunnel. Is configured to be elastically biased toward the outer surface of the other tunnel.

  According to the water stop structure of such a configuration, it is possible to perform the water stop construction simply by providing an elastic seal member on the outer surface of the tunnel and propelling the tunnel. It becomes easy. Furthermore, since the elastic seal member has a lip portion that is elastically biased toward the outer surface of the other adjacent tunnel by the pressure of the ground outside the large cross-section tunnel, Adhesiveness becomes high and water stop can be improved.

JP 2006-90098 A JP 2010-133100 A

  In the water stop structure as in Patent Document 2, since the earth pressure of the natural ground is applied to the front end portion in the propulsion direction of the elastic seal member when the tunnel is propelled, a configuration for protecting the front end portion is necessary. Patent Document 2 describes a configuration in which a leading cover 102 is provided at the front end portion in the propulsion direction of the elastic seal member 101 as shown in FIG. The leading cover 102 is a member provided so as to cover the front end surface of the elastic seal member 101, and is formed of a hard resin or steel member. The leading cover 102 is formed so as to be thicker from the front end toward the rear, so that when the tunnel 100 is propelled, the earth and sand of the front ground is pushed away from the position where the elastic seal member 101 passes. ing. By the way, when the succeeding tunnel swings during propulsion, the distance between the tunnels fluctuates. However, since the leading cover 102 does not have elasticity, it is difficult to follow this fluctuation.

  From such a point of view, an object of the present invention is to provide a seal front end protection structure that can protect the front end of an elastic seal member while responding to swinging of a tunnel during propulsion.

The present invention, which was created to solve such problems, is used to stop water between the inside and outside of a large section tunnel constructed by using a plurality of tunnels arranged side by side by the propulsion method. A protective structure for protecting a front end portion of an elastic seal member provided along a propulsion direction between a matching preceding tunnel and a succeeding tunnel, the storage cap member storing the front end portion of the elastic seal member, and the storage A soil removal member provided in front of the propulsion direction with respect to the cap member, and the elastic seal member is provided on a surface of the succeeding tunnel facing the preceding tunnel, A housing portion for housing the elastic seal member in a contracted state, and the earth discharging member is a position where the elastic seal member passes between the preceding tunnel and the subsequent tunnel. A sealing front end protective structure, characterized in that to eliminate sediment.

  According to such a structure, since the accommodation cap member is comprised so that it may accommodate in the state which shortened the elastic seal member, height becomes low. Therefore, two adjacent tunnels can be close to each other. Furthermore, by providing the earth removing member, the elastic sealing member can be prevented from coming into contact with the earth and sand, so that the protection performance of the elastic sealing member is enhanced.

Further, the earth removing member is formed by fixing a wire brush surrounded by a leaf spring to a mounting base, and is separated from the trailing tunnel as it goes rearward in the propulsion direction. Is preferred.

  Further, a seal accommodation groove extending along the propulsion direction is formed in the trailing tunnel, and the soil removal member, the accommodation cap member, and the elastic seal member are accommodated in the seal accommodation groove. Those are preferred. According to such a configuration, it is possible to reduce the portions of the earth removing member, the storage cap member, and the elastic seal member that are in contact with the natural ground, so that the wear of each member is suppressed and the protection performance can be improved.

  According to the seal front end protection structure of the present invention, it is possible to protect the front end of the elastic seal member while supporting the swinging of the tunnel during propulsion.

It is the side view which showed the seal front end part protection structure which concerns on embodiment of this invention, Comprising: (a) is a figure in case the distance between adjacent tunnels is large, (b) is a figure in case the distance between tunnels is small It is. It is the perspective view which showed the accommodation cap member of the seal front end protection structure which concerns on embodiment of this invention, Comprising: (a) is the figure seen from the propulsion direction front side of a tunnel, (b) is seen from the propulsion direction rear side. It is a figure. It is the perspective view which showed the propulsion direction front end part of the elastic seal member at the time of application of the seal front end part protection structure according to the embodiment of the present invention. It is the sectional view on the aa line of FIG. It is the perspective view which showed the earth discharging member of the seal front-end part protection structure which concerns on embodiment of this invention. It is the bb sectional view taken on the line of FIG. It is the perspective view which showed the modification of the earth discharging member of the seal front-end part protection structure which concerns on embodiment of this invention. It is sectional drawing which showed the large section tunnel. FIG. 9 is an enlarged cross-sectional view illustrating a portion X1 in FIG. 8. (A) And (b) is the perspective view which showed the front-end part of the conventional water stop structure.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the present embodiment, the front-rear direction indicates the front-rear direction of the tunnel box constituting the tunnel.

  As shown in FIG. 8, the water stop structure W <b> 1 includes an inside (inner space portion) and an outside (natural mountain portion) of the large section tunnel 1 constructed by using a plurality of tunnels 10 arranged in parallel by the propulsion method. It is a structure that stops water between. The large-section tunnel 1 is constructed by using a plurality of (six in this embodiment) tunnels 10, 10,... Arranged side by side so as to substantially include all of the transverse sections. A plate 1A, a bottom plate 1B, and side walls 1C and 1C are provided. Each tunnel 10 is configured by a tunnel box connected in the axial direction.

  As shown in FIG. 9, of the two adjacent tunnels 10, 10, the leading tunnel 10 b has a guide groove D <b> 1 opening on the trailing tunnel 10 a side along the tunnel axis direction (perpendicular to the paper surface in FIG. 9). The ridge P1 is formed in the trailing tunnel 10a so as to be loosely fitted in the guide groove D1 of the preceding tunnel 10b. Hereinafter, the guide groove D1 and the protrusion P1 may be simply referred to as “joint J1”. And the water stop structure W1 is formed in the outer side (natural ground side) of the large cross section tunnel 1 rather than this joint J1. That is, the joint J1 and the water stop structure W1 are provided separately.

As shown in FIG. 1, the water stop structure W <b> 1 includes an elastic seal member 30. The seal front end protection structure W2 that protects the front end of the water stop structure W1 includes an accommodation cap member 50 and a soil removal member 70. The water stop structure W1 is provided over the entire length of the trailing tunnel 10a along the propulsion direction, and the seal front end protection structure W2 is provided in the leading tunnel box of the trailing tunnel 10a.

The elastic seal member 30 is accommodated in a seal accommodation groove 15 (see FIG. 9) formed on the outer peripheral surface of the trailing tunnel 10a. 1 to 7, the trailing tunnel 10a is shown on the lower side.

  As shown in FIG. 9, the elastic seal member 30 is a member provided along the propulsion direction between two adjacent tunnels 10 and 10. The elastic seal member 30 is provided in a portion of the surface of one tunnel 10 (following tunnel 10a) facing the other tunnel 10 (preceding tunnel 10b). The elastic seal member 30 is made of a material such as hard rubber or urethane having wear resistance, for example. The elastic seal member 30 is provided continuously in the propulsion direction. The elastic seal member 30 includes a base portion 31 and a lip portion 32.

  The base portion 31 is a portion fixed to the outer surface of the trailing tunnel 10a, is formed in a long plate shape, and extends in the propulsion direction. The base portion 31 is fixed to the outer surface of the trailing tunnel 10a (the bottom surface of a seal receiving groove 15 described later) by fixing means such as a bolt B or an adhesive. The base portion 31 is formed with a bolt through hole 35 formed by a long hole (see FIG. 3) that is long in the propulsion direction, and the fixing position can be adjusted. An adhesive layer (not shown) formed by applying an adhesive is formed on the bottom surface of the seal housing groove 15. That is, the base portion 31 is in close contact with the bottom surface of the seal housing groove 15 via the adhesive layer, and the sealing property between the outer surface of the subsequent tunnel 10a and the base portion 31 is ensured by the adhesive layer.

  The lip portion 32 is formed integrally with the base portion 31. The lip portion 32 rises obliquely from the surface of the base portion 31 toward the preceding tunnel 10b, and the cross section of the base portion 31 and the lip portion 32 is substantially V-shaped. The lip portion 32 is a portion that can be elastically tilted and deformed with respect to the base portion 31. The lip portion 32 is sandwiched between the succeeding tunnel 10a and the preceding tunnel 10b, and comes into contact with the outer surface of the preceding tunnel 10b in a tilted state from the initial state (indicated by a two-dot chain line in FIG. 9). . At this time, the lip portion 32 is elastically biased toward the preceding tunnel 10b by the force to be restored.

  Furthermore, the elastic seal member 30 is disposed so that the tip of the lip portion 32 faces the outside of the large-section tunnel 1. That is, a groove having a substantially V-shaped cross section formed by the base portion 31 and the lip portion 32 is disposed so as to open toward the outside of the large cross-section tunnel 1. As a result, the pressure (water pressure) outside the large-section tunnel 1 acts on the groove portion of the elastic seal member 30 having a substantially V-shaped section. That is, the lip portion 32 is pressed against the outer surface of the preceding tunnel 10b by the pressure (water pressure) outside the large-section tunnel 1 and is in close contact with the preceding tunnel 10b.

  The seal housing groove 15 is formed in a portion of the surface of the trailing tunnel 10a that faces the preceding tunnel 10b, and extends along the propulsion direction. The seal housing groove 15 has a rectangular cross section, and is partitioned by side plates 16 a and 16 a and a bottom plate 16 b which are fixed by welding inside an opening 11 a formed in the skin plate 11 on the surface of the tunnel 10. The seal accommodating groove 15 has a width dimension slightly larger than the width dimension of the elastic seal member 30 so that the elastic seal member 30 can be accommodated. As shown in FIG. 1, the seal accommodation groove 15 has a depth dimension that is larger than the thickness dimension of the base portion 31 and smaller than the thickness dimension of the entire elastic seal member 30. When housed in the groove 15, a part of the distal end side of the lip portion 32 (the side opposite to the base end side connected to the base portion 31) projects from the open end of the seal housing groove 15. In addition to the elastic seal member 30, the storage cap member 50 and the soil removal member 70 are stored in the seal storage groove 15. These members are housed in the seal housing groove 15 in the order of the soil removal member 70, the housing cap member 50, and the elastic seal member 30 from the front in the propulsion direction.

  In this embodiment, the elastic seal member 30 has a substantially V-shaped cross section. However, the elastic seal member 30 is not intended to limit the cross-sectional shape of the elastic seal member 30. For example, other shapes such as a U-shaped section, an L-shape, and a T-shape may be used.

  As shown in FIG. 1, the housing cap member 50 is a member that houses the front end portion of the elastic seal member (the front end portion in the propulsion direction of the tunnel 10). The housing cap member 50 is made of a material having excellent wear resistance such as metal. The storage cap member 50 is thinner toward the front. The front end portion of the housing cap member 50 has a thickness dimension smaller than the depth dimension of the seal housing groove 15, and the rear end section has a thickness dimension larger than the depth dimension of the seal housing groove 15. Yes. The thickness dimension of the rear end portion is a projection dimension of the accommodation cap member 50 from the steel shell surface of the tunnel 10 (a value obtained by subtracting the depth dimension of the seal accommodation groove 15 from the thickness dimension of the accommodation cap member 50). It is set to be smaller than the minimum separation dimension (for example, 10 mm) between the adjacent tunnels 10 and 10. As the accommodation cap member 50 becomes thinner as it goes forward, the accommodation portion 51 inside thereof also becomes thinner as it goes forward.

  As shown in FIG. 2, the storage cap member 50 has a convex shape with a thick intermediate portion in the width direction. The storage cap member 50 includes a storage portion 51 that opens rearward. As shown in FIG. 4, the cross-sectional shape of the accommodating portion 51 at the rear end of the accommodating cap member 50 is formed so that the lip portion 32 of the elastic seal member 30 can be accommodated in a state of being inclined toward the base portion 31 side. That is, the rear end accommodating portion 51 includes a wide portion 51 a that accommodates the base portion 31 and a narrow portion 51 b that accommodates the lip portion 32. The wide part 51a and the narrow part 51b are continuously formed integrally.

  As shown in FIG. 1, the thickness of the accommodating portion 51 at the front end of the accommodating cap member 50 is thinner than the thickness of the accommodating portion 51 at the rear end. Similarly to the rear end, the front-end accommodating portion 51 includes a wide portion 51a and a narrow portion 51b. The wide portion 51a has the same shape from the rear end to the front end. The width of the narrow portion 51b decreases from the rear end to the front end.

  As shown in FIG. 2, a bolt through hole 52 is formed in a portion located outward of the narrow portion 51 b in the width direction and above the wide portion 51 a (on the opening end side of the seal housing groove 15). The bolt through hole 52 is formed at a position corresponding to the bolt hole 34 of the elastic seal member 30 inserted into the housing portion 51. The bolt through hole 52 is a long hole that is long in the propulsion direction, and the fixing position can be adjusted. As shown in FIG. 4, a boss portion 76 having a through hole 77 and having a screw hole in the lower part is welded and fixed at a position where the receiving cap member 50 of the bottom plate 16 b of the seal receiving groove 15 is fixed. . The bolt B is penetrated from the bolt through hole 52 of the housing cap member 50 to the bolt hole 34 of the elastic seal member 30 and the through hole 77 of the seal housing groove 15, and is screwed into the boss portion 76. The member 30 and the accommodation cap member 50 are fixed to the seal accommodation groove 15.

  As shown in FIGS. 1 and 3, the front end portion of the lip portion 32 of the elastic seal member 30 gradually decreases in thickness toward the front. The thin-walled portion at the front end of the lip portion 32 is formed thinner by scraping more as the surface is moved forward. In this way, an inclined surface is formed at the front end portion of the elastic seal member 30, and this inclined surface serves as a guide when inserted into the elastic seal member 30, so that the accommodating portion 51 whose front end portion is thin is elastic. It becomes easy to insert the seal member 30.

  Further, a reduction portion 33 is formed in a portion of the base portion 31 that is accommodated in the accommodation portion 51. The reduced portion 33 is formed by cutting away both side surfaces and the bottom surface in the width direction of the base portion 31 by a predetermined thickness, and is narrower and thinner than the base portion 31 in other portions. . The thickness of the part to be cut is equal to the wall portions 53 (see FIGS. 2 and 4) located on both sides and the bottom of the wide portion 51a of the accommodating cap member 50. That is, the cross section of the reduced portion 33 has the same shape as the cross section of the wide portion 51 a of the accommodating portion 51. Therefore, when the reduced portion 33 of the elastic seal member 30 is inserted into the storage portion 51 of the storage cap member 50, the side surface and the bottom surface of the rear elastic seal member 30 excluding the reduction portion 33 are the side surface of the storage cap member 50 and Each surface is flush with the bottom surface, and each surface is continuously connected. Thereby, when the accommodation cap member 50 and the elastic seal member 30 are accommodated in the seal accommodation groove 15, no gap is generated on the inner peripheral surface of the seal accommodation groove 15, and the water stop performance can be improved.

  As shown in FIG. 4, the elastic seal member 30 having the above-described configuration is restored when the lip portion 32 is elastically inclined with respect to the base portion 31 when inserted into the accommodating portion 51. The inner peripheral surface of the accommodating portion 51 is pressed by the force described above. Thereby, the storage cap member 50 and the elastic seal member 30 are fixed and integrated.

  As shown in FIG. 1, the earth discharging member 70 is a member that is provided in front of the housing cap member 50 and pushes away the earth and sand in the propulsion direction of the elastic seal member 30 from the passage path of the elastic seal member 30. The earth removing member 70 is configured by fixing a wire brush 72 surrounded by a leaf spring 71 to an attachment base 73. The mounting base 73 is made of a plate material made of hard rubber, urethane, or the like. As shown in FIGS. 5 and 6, the mounting base 73 is slightly smaller than the width of the seal housing groove 15 (the elastic seal member 30 and the housing cap member 50 so as to be housed in the seal housing groove 15. The same width dimension). The mounting base 73 has a thickness dimension smaller than the depth dimension of the seal accommodation groove 15, and the whole is accommodated in the seal accommodation groove 15. Bolt holes 74 a and 74 b are formed in the mounting base 73.

  As shown in FIG. 1, the spring 71 is formed by bending a metal plate, for example. The leaf spring 71 is disposed so as to surround the bottom side (the bottom side of the seal housing groove 15) and the upper side (the preceding tunnel 10b side) of the wire brush 72 from the front in the propulsion direction, and also has a protection function for the wire brush 72. ing. The leaf spring 71 includes a parallel portion 71a parallel to the surface of the mounting base 73, and an inclined portion 71b bent toward the preceding tunnel 10b behind the parallel portion 71a. A mounting portion 71c is fixed in front of the parallel portion 71a. A plurality of bolt through holes 75 (see FIG. 6) are formed in the mounting portion 71c, and the base end portion of the leaf spring 71 is fixed to the mounting base 73 by a fixing means such as a bolt B. The bolt holes 74a of the mounting base 73 positioned at both ends in the width direction are formed so as to penetrate therethrough, and the bolts B positioned at both ends in the width direction pass through to the lower side of the bottom plate 16b of the seal housing groove 15 to form screw holes. And is screwed into a boss portion 76 having. The boss portion 76 is fixed by welding to the lower portion of the through hole 77 of the bottom plate 16b. With such a configuration, the soil removal member 70 is fixed to the seal housing groove 15. The bolt hole 74b of the mounting base 73 located in the center in the width direction has a thread groove, and the leaf spring 71 and the mounting base 73 are fixed by screwing the bolt B inserted through the mounting portion 71c. Is done.

  When the earth discharging member 70 is fixed to the seal housing groove 15, the inclined portion 71b is inclined so as to be separated from the succeeding tunnel 10a toward the rear. And the rear end side of the inclined part 71b protrudes toward the preceding tunnel 10b side from the steel shell surface of the succeeding tunnel 10a. The inclined portion 71b is closer to the preceding tunnel 10b toward the rear. The protruding dimension of the inclined portion 71b (the protruding dimension of the rear end) is set to be larger than the maximum separation dimension (for example, 40 mm) between the adjacent tunnels 10 and 10. That is, the inclined portion 71b is always pressed against the preceding tunnel 10b, and the inclined portion 71b is in contact with the steel shell surface of the preceding tunnel 10b by its restoring force. The inclined portion 71b has a rear end located behind the mounting base 73, and covers the surface of the accommodation cap member 50 when pressed against the trailing tunnel 10a.

  As shown in FIG. 1, the upper and lower surfaces of the wire brush 72 are surrounded by a leaf spring 71 from the front end side, and are fixed to the mounting base 73 integrally with the leaf spring 71 via bolts B. The rear end side of the wire brush 72 extends obliquely rearward as viewed from the side, and a part of the wire brush 72 slides in contact with the steel shell surface of the preceding tunnel 10b. The wire brush 72 is formed in a three-layer structure in the thickness direction, and a partition plate is provided between the layers. The gap in the wire brush 72 is filled with grease or urethane foam. The wire brush 72 and the leaf spring 71 have the same width as the mounting base 73 and are disposed over the entire width of the seal housing groove 15.

  According to the seal front end protection structure W2 configured as described above, the front end of the elastic seal member 30 can be protected because the front end of the elastic seal member 30 is inserted into the housing cap member 50. Thereby, peeling of the front end portion of the elastic seal member 30 can be prevented. And since this accommodation cap member 50 is comprised so that the elastic seal member 30 may be accommodated in the compressed state, the protrusion amount from the surface of the succeeding tunnel 10a may be small. As a result, the two adjacent tunnels 10 and 10 can be close to each other. Specifically, the accommodating cap member 50 is set so that the projecting dimension of the tunnel 10 from the steel shell surface is smaller than the minimum separation dimension between the adjacent tunnels 10, 10 (b in FIG. ), The trailing tunnel 10a can be close to the preceding tunnel 10b to the minimum separation dimension.

  Furthermore, since the earth discharging member 70 is provided in front of the housing cap member 50, the earth and sand can be removed from the passage path of the elastic seal member 30. Thereby, it can suppress that the elastic seal member 30 contacts earth and sand, and can improve the protection performance of the elastic seal member 30. The earth removal member 70 includes leaf springs 71 that extend toward the preceding tunnel 10b and that can be deformed according to the separation distance between the preceding tunnel 10b and the succeeding tunnel 10a. Even if the two tunnels 10 and 10 are close to or separated from each other, the soil removal member 70 is always in contact with the surface of the preceding tunnel 10b. Therefore, as shown in FIG. 1 (a), even if the trailing tunnel 10a is separated from the preceding tunnel 10b to the maximum separation dimension, the earth discharging member 70 can always exhibit the earth discharging function. The protection performance of the elastic seal member 30 can be ensured.

  As described above, according to the seal front end protection structure W <b> 2, it is possible to cope with the swinging of the tunnel 10 during propulsion and to exhibit the excellent effect that the front end of the elastic seal member 30 can be protected.

  In this embodiment, since the elastic seal member 30 includes the base portion 31 and the lip portion 32, the elastic seal member 30 is easily deformed. Therefore, it is easy to perform the operation of accommodating in the accommodating cap member 50 in a compressed state. Furthermore, since the lip part 32 is elastically contacted toward the outer surface of the preceding tunnel 10b by the pressure outside the large-section tunnel 1, the water stopping performance is high.

  Further, a seal receiving groove 15 is formed in the trailing tunnel 10a, and the earth discharging member 70, the receiving cap member 50, and the elastic seal member 30 are sequentially stored in the seal receiving groove 15 from the front in the propulsion direction. The part which contacts the natural ground of the member of this can be reduced. Therefore, the wear of each member is suppressed and the protection performance can be enhanced.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to the said embodiment, In the range which does not deviate from the meaning of this invention, a design change is possible suitably. For example, the earth discharging member 70 according to the embodiment is configured to include the wire brush 72, but is not limited to such a configuration. For example, as shown in FIG. 7, the soil removal member may be made of the same material as the elastic seal member 30. In this case, the soil removal member 78 includes a base portion 78a and a rising portion 78b. The rising portion 78b extends in a direction orthogonal to the propulsion direction, and rises obliquely backward from the surface of the base portion 78a in the propulsion direction. A through hole 79 for a bolt is formed in a portion of the base portion 78a located before and after the rising portion 78b. Bolts are inserted through the through holes 79 to fix the soil removal member 78 to the mounting base 73. In the embodiment, the earth removing members 70 and 78 are fixed to the tunnel 10 via the mounting base 73, but may be directly fixed to the bottom of the seal housing groove 15.

W1 Water stop structure W2 Seal front end protection structure 1 Large section tunnel 10 Tunnel 10a Trailing tunnel 10b Lead tunnel 15 Seal receiving groove 30 Elastic seal member 31 Base portion 32 Lip portion 50 Housing cap member 70 Earth removing member

Claims (3)

Provided along the propulsion direction between the adjacent preceding tunnel and the succeeding tunnel to stop water between the inside and outside of the large section tunnel constructed using multiple tunnels arranged side by side with the propulsion method. A protective structure for protecting the front end of the elastic seal member,
An accommodation cap member that accommodates the front end of the elastic seal member; and a soil removal member that is provided in front of the accommodation cap member in the propulsion direction ,
The elastic seal member is provided on a surface of the trailing tunnel facing the preceding tunnel,
The accommodating cap member includes an accommodating portion that accommodates the elastic seal member in a contracted state.
The structure for protecting the front end of a seal, wherein the earth removing member excludes the earth and sand at a position where the elastic seal member passes between the preceding tunnel and the following tunnel. The earth removing member is formed by fixing a wire brush surrounded by a leaf spring to a mounting base, and is separated from the trailing tunnel toward the rear in the propulsion direction. The seal front end protection structure according to claim 1. Provided along the propulsion direction between the adjacent preceding tunnel and the succeeding tunnel to stop water between the inside and outside of the large section tunnel constructed using multiple tunnels arranged side by side with the propulsion method. A protective structure for protecting the front end of the elastic seal member,
A storage cap member for storing the front end portion of the elastic seal member, and a soil removal member provided in front of the storage cap member;
The elastic seal member is provided on a surface of the trailing tunnel facing the preceding tunnel,
The accommodating cap member includes an accommodating portion that accommodates the elastic seal member in a contracted state.
The soil removal member is configured to exclude soil and sand at a position where the elastic seal member passes between the preceding tunnel and the subsequent tunnel,
The trailing tunnel is formed with a seal accommodation groove extending along the propulsion direction,
The seal front end protection structure, wherein the soil removal member, the storage cap member, and the elastic seal member are stored in the seal storage groove.

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